Subthreshold transpupillary thermotherapy for early resolution of foveal subretinal fluid in choroidal metastasis

Abstract

Purpose: To report the effectiveness of subthreshold transpupillary thermotherapy (TTT) in the early resolution of subretinal fluid at the fovea in solitary choroidal metastasis.

Methods: : Three consecutive patients who had adenocarcinoma of the lung with choroidal metastasis and macular subretinal fluid were treated by subthreshold TTT. Tumor response and fluorescein angiographic and visual results were recorded.

Results: Fluorescein angiography revealed solitary choroidal metastasis at the posterior pole with subretinal fluid in all patients. Initial best-corrected visual acuity in Patient 1, a 57-year-old man, was 40/200. Instead of usual high laser intensity, three applications of TTT, 400-mW power, 3-mm size, and 1-minute duration, were performed over the tumor mass. Repeated treatment with the same regimen was performed after 1 week. Visual acuity improved to 20/25 2 months after treatment. Best-corrected visual acuity in Patient 2, a 68-year-old woman, was 10/200 in the right eye before treatment. Visual acuity improved to 80/200 after treatment and remained stable for 14 months. Visual acuity improved from 20/100 to 20/60 in a third patient 2 months after treatment. The disappearance of subretinal fluid over the fovea was noted by fluorescein angiography 2 months after laser treatment and remained stable until the end of follow-up.

Conclusion: Improvement of visual acuity and cessation of fluorescein leakage in the tumor showed that subthreshold (i.e., biomicroscopically invisible laser effect) TTT served as an effective treatment modality in the early resolution of macular subretinal fluid in choroidal metastasis. Multiple sessions of subthreshold TTT are safe to apply very close to the macula.